Lincoln Impinger Conveyor Oven Series 1000 - Manual (Page 7)

Impinger I -–1000 Series Service Manual - International 7
14 VAC) with a center tap, and supplies power to the Time/Temp Display. The
voltage from each leg of the Transformer's secondary to the center tap should be
one half of the secondary voltage
BURNER CIRCUIT Closing the normally open Burner Switch supplies 220 VAC, through the gas
pressure-proving switch, and through the Main Fan Air Pressure Switch, to the
Ignition Control. The combustion motor relay is energized, its normally open contacts
now close, supplying120 VAC to the combustion motor. The normally open
combustion air switch closes upon sensing air. After pre-purge period of between 30
and 60 seconds, the Ignition Transformer is energized and the Main Gas Valve is
energized. Ignition should now occur.
TEMPERATURE
CONTROL
Closing the Fan Switch supplies (through the Step down Transformer) 120 VAC to
the Temperature Control Board. The 2.5K ohm Temperature Potentiometer is
adjusted to desired temperature. The Thermocouple will provide varying millivolts to
the Temperature Controller. The Temperature Controller supplies 120 VAC to the
Solenoid Valve at intermittent intervals to maintain desired temperature.
CONVEYOR DRIVE
(S/N4390-Q17170)
(Conveyor Drive
Q171701 & Above See
Page 9)
Closing the fan switch and the normally open conveyor switch supplies 120 VAC to
the Motor Control Board. AC volts are converted to DC volts and are supplied to the
Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control
Potentiometer (5,000 ohm 10 turn) will change resistance at terminals P1, P2, and
P3 varying the DC voltage to the Conveyor Motor. The speed of the conveyor motor
will increase or decrease as the DC voltage from the board increases or decreases
respectively. As the motor turns, it drives both the reducer gearbox and the tach.
generator. The tach. generator is a DC voltage generator which supplies a voltage to
the DC motor control board and is used as a reference for maintaining a constant
conveyor speed.
(Time/Temp Display
Q17171 & Above See
Page 9)
The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120
VAC to the primary of the 12.6 volt Transformer. The secondary output of the
transformer, normally 13 to 14 VAC (depending on input), with a center tap, is
supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is
terminal 2. The display works on a balanced input and center tap voltage to each leg
must be 1/2 the total reading.
TIME/TEMP
DISPLAY(Q17171 &
Above See Page 9
The speed side of the Time Temp. Display uses a slotted disc (cemented to tach.
coupling) to break the infra-red light beam of the optical switch (mounted on gear
motor) producing electrical pulses that are transmitted to the display. The display
converts these pulses into a read-out of minutes and seconds.
The temperature portion of the display uses a Thermistor Probe to sense oven
temperature. The thermistor outputs a resistance proportional to the oven
temperature. This resistance is then converted by the display into a temperature
reading.
SEQUENCE OF OPERTIONS 1032
MODEL 1032 - 380Y/220 VAC - 50 HZ - 3 PHASE
POWER SUPPLY Electrical Power to be supplied to the Oven by a five conductor service
Black conductor is Hot
Red conductor is Hot
Orange conductor is Hot
White conductor is Dedicated Neutral
Green conductor is Ground
MAIN FAN CIRCUIT Electrical power is permanently supplied through 3, 50A fuses to the normally open
contacts of the Mercury Contactor. Power is also supplied through one 10A fuse to
the normally open contact of the Main Fan Relay, through a 1A Fuse to the normally
open Double Pole Main Fan Switch, and to the normally open Cool-Down
Thermostat (thermostat closes at 160°F and opens at 140°F.) Closing the Main Fan
Switch supplies 220VAC to the primary of the control circuit Step Down Transformer.
(The transformer steps the voltage down to 120 VAC for the control circuit.) 120 VAC
is supplied to the coil of the Main Fan Relay. The coil of the relay is energized, the
normally open contacts close, energizing the Main Fan Motor. Closing the Main Fan
Switch also supplies power to the 12.6 VAC Transformer, the Control Box Cooling